QUESTION: WITH AC POWER, AREN'T BOTH WIRES OF THE PAIR INTERCHANGABLE? Why is one wire called "neutral?" What's all this stuff about "grounding?" Why are three prongs needed? Also see below: WHY "GROUND" IS CONFUSING __________________________ / \ / _ \ | | | _ | | | | | | | | | | | | | | | | | | | | | | | | | | | | |_| | | |_| | | ____ | | / \ | | | | | | |______| | \ / \_____________________